I see there are two methods for opening a document
public int Open( String path, String opassword, String upassword )
public int OpenMem( byte data, String opassword, String upassword )
it there a chance for you to provide also a method that uses streams instead of a byte?
What we are intrested in is having the pdfs stored encrypted (using our own implementation) on the sd card and decrypting them on the fly (without using a temp-decrypted file). The byte method could work but since some of our pdfs are 80mb big, i doubt that android phones can hold all that in memory.
The performance is an issue i guess but it depends on the actual algorithm and shouldn't bother you. One could just perform a simple xor every x number of bytes (so it;s really a scrambled file) and this will have no impact on the reading if we are talking about streams.